Process of Straightening by Three-Point and Four-Point Bending for Curved Brass Rack
Yuuta Aono*,, Nobukatsu Sato**, Shinji Inoue**, and Daichi Koga**
*National Institute of Technology, Kurume College
1-1-1 Komorino, Kurume, Fukuoka 830-8555, Japan
**Koga Gear Product Company, Kurume, Japan
Racks are typically curved after cutting their gear teeth, and a straightening process is required to correct the distortion due to machining. In this study, key factors in the straightening of curved racks by three-point and four-point bending are examined with to automate the correction. The relationship between load and deformation is plotted in real time to determine the unloading point to correct the target deflection for straightening. The parameters constituting the above-mentioned relationship are important for achieving precise correction. The load and deflection at the central loading point are known to be suitable parameters for three-point bending. The smaller the deflection required for correction, the higher is the precision of the displacement sensor required for three-point bending. In the case of four-point bending, the bending moment and bending angle should be selected. In addition, a four-point bending jig is required to load the uniform bending moment during the correction. A modified four-point bending jig is made and the effectiveness was examined.
-  KHK Gear Industry Website. https://khkgears.net/new/gear_knowledge/introduction_to_gears/production-processes-of-gear-rack.html [Accessed February 22, 2022]
-  H. Tokunaga, “On the Roller Straightener: Report 1, Straightening of Sections,” JSME Int. J. Series B, Vol.3, No.12, pp. 572-579, doi: 10.1299/JSME1958.3.572, 1960.
-  H. Tokunaga, “On the Roller Straightener: 2nd Report, Straightening of Round Bars, Pipe and Tubing,” JSME Int. J. Series B, Vol.4, No.15, pp. 605-661, doi: 10.1299/kikai1938.26.1720, 1961.
-  N. K. Das Talukder and A. N. Singh, “Mechanics of Bar Straightening, Part 1: General Analysis of Straightening Process,” J. of Engineering for Industry, Vol.113, No.2, pp. 224-227, doi: 10.1115/1.2899682, 1991.
-  N. K. Das Talukder and A. N. Singh, “Mechanics of Bar Straightening, Part 2: Straightening in Cross-Roll Straighteners,” J. of Engineering for Industry, Vol.113, No.2, pp. 224-227, doi: 10.1115/1.2899683, 1991.
-  B. Biju, J. S. Dijin, C. Anujith, A. Arun, and A. P. Mohammad, “Designing and Analysis of Straightening Mechanism for Commercial Steel Bars,” Int. Research J. of Engineering and Technology, Vol.3, pp. 379-383, 2016.
-  B. J. Wu, L. C. Chan, T. C. Lee, and L. W. Ao, “A Study on the Precision Modeling of the Bars Produced in Two Cross-roll Straightening,” J. of Materials Processing Technology, Vol.99, pp. 202-206, doi: 10.1016/S0924-0136(99)00421-5, 2000.
-  R. Creal, “Automated Straightener Eliminates Bottleneck,” Heat Treating, Vol.19, No.8, pp. 19-20, 1987.
-  PLEVA GmbH Pamphlet of Straightening Systems. https://www.leclairmeert.be/files/9615/7285/7716/Prospekt_SL_SD_series_300.pdf [Accessed February 22, 2022]
-  Cesare Galdabini S.p.a Pamphlet of Straightening Systems. http://www.belfor.es/representadas/catalogos/galdabini/GALDABINI_ST_Catalogue_en_01_2014LR.pdf [Accessed February 22, 2022]
-  Maschinen- und Apparatebau Götzen GmbH Pamphlet of Automatic Straightening Systems. https://www.mae-group.com/tl_files/fotos/downloads/MAE%20Automatic%20straightening%20machines%20-%20M-AH.pdf [Accessed February 22, 2022]
-  Stierli-Bieger Website of Metal Straightening Machines. https://www.stierli-bieger.com/en/areas-of-application/38-metal-straightening-with-straightening-machines.html [Accessed February 22, 2022]
-  “Correction Device,” Japanese Patent, H5-65505, 1993.
-  “Correction Device,” Japanese Patent, H5-148979, 1993.
-  “Device for Correcting Distortion of Long Rod,” Japanese Patent, H7-265954, 1994.
-  “Method and Device for Correcting Distortion of Long Rod,” Japanese Patent, H7-112038, 1995.
-  “Device for Correcting Distortion and Method,” Japanese Patent, H5-93322, 1993.
-  “Detection Method of Correction Value, Method and Device for Correcting Distortion,” Japanese Patent, H8-57968, 1996.
-  “Method and Device for Correcting Distortion,” Japanese Patent, P2003-123428, 2003.
-  “Method and Device for Correcting Distortion,” Japanese Patent, P2003-123780, 2003.
-  “Method for Correcting Distortion,” Japanese Patent, P2011-214470, 2011.
-  “Machine for Correcting Distortion,” Japanese Patent, P2013-178315, 2013.
-  F. Yoshida, T. Uemori, and K. Fujiwara, “Elastic-Plastic Behavior of Steel Sheets under In-Plane Cyclic Tension-Compression at Large Strain,” Int. J. of Plasticity, Vol.18, pp. 633-659, doi: 10.1016/S0749-6419(01)00049-3, 2002.
-  F. Yoshida, T. Uemori, and K. Fujiwara, “A Model of Large-Strain Cyclic Plasticity Describing the Bauschinger Effect and Workhardening Stagnation,” Int. J. of Plasticity, Vol.18, pp. 661-686, doi: 10.1016/S0749-6419(01)00050-X, 2002.
-  R. Mena, J. V. Aguado, S. Guinard, and A. Huerta, “Post-machining distortion mitigation via bending straightening, a multiparametric ROM study,” Proc. of the 22nd Int. ESA FORM Conf. on Material Forming, hal-02454607, doi: 10.1063/1.5112642, 2019.
-  X. Huang, J. Zhao, G. Yu, Q. Meng, Z. Mu, and Y. Liu, “Multi-point Flexible Straightening Process by Reciprocating Bending for Metal Profiles,” Trans. of Nonferrous Metals Society of China, Vol.31, pp. 2039-2050, doi: 10.1016/S1003-6326(21)65636-4, 2021.
-  Q. Meng, G. Yu, X. Huang, H. Sun, and J. Zhao, “Study on a Straightening Process by Reciprocating Bending for Metal Profiles,” Metallurgical Research and Technology, Vol.118, No.6, 605, doi: 10.1051/metal/2021081, 2021.
This article is published under a Creative Commons Attribution-NoDerivatives 4.0 Internationa License.